Not hitting all grain FG goals

[Tiddy]

Hey guys,

I have been brewing partial mash batches for last ten years..about one every couple weeks and finally made the jump to all grain.

I have brewed three batches so far, a stout and two IPAs. I am using a single step infusion mash in a modified keggle. My OGs are pretty close to exactly as I need but the final gravities are stalling out pretty regularly at .02 higher than i need. This last IPA started at a 1.048 and is now stalled at a 1.025.

I'm steeping at 152-154 and fermenting with two smack packs of 1056 @ 68-69 deg.

I've never had problems with stuck or regularly failing fermentations and can't figure out where the deal. Any ideas?

 

[Onkel_Udo]

Hey guys,

I have been brewing partial mash batches for last ten years..about one every couple weeks and finally made the jump to all grain.

I have brewed three batches so far, a stout and two IPAs. I am using a single step infusion mash in a modified keggle. My OGs are pretty close to exactly as I need but the final gravities are stalling out pretty regularly at .02 higher than i need. This last IPA started at a 1.048 and is now stalled at a 1.025.

I'm steeping at 152-154 and fermenting with two smack packs of 1056 @ 68-69 deg.

I've never had problems with stuck or regularly failing fermentations and can't figure out where the deal. Any ideas?

Have u calibrated your thermometer lately? How are you measuring gravity? Yeast? Temperature?

 

[aviator01]

Check/calibrate your thermometer to make sure your at your target temps. Or if your lazy like me, just mash at slightly lower temperature 149-151 and see if it makes a difference.

I got one of my thermometers a bit hot and now it reads about 7 degrees hot. This could have caused some issues if I hadn't caught it right away.

 

[tsl346]

How are you measuring your FG? A refractometer can be used for OG, but not for FG. You will need to use a hydrometer to measure your FG.

 

[Tiddy]

I'm using a True Brew floating thermometer. The closest I came to calibration was to see what it read 212 when the water starts boiling. I'll invest in a digital. Perhaps the $5 thermometer is no longer cutting it.

I measure my gravities pre and post boil using a refractometer that I calibrate at room temperature using distilled water. I keep the brew in my bedroom closet where the house is heated at 68 degrees. Newer house so temps are good..no drafts or cold spots in rooms.

As for yeast I just use the two slap packs

 

[Onkel_Udo]

I'm using a True Brew floating thermometer. The closest I came to calibration was to see what it read 212 when the water starts boiling. I'll invest in a digital. Perhaps the $5 thermometer is no longer cutting it.

I measure my gravities pre and post boil using a refractometer that I calibrate at room temperature using distilled water. I keep the brew in my bedroom closet where the house is heated at 68 degrees. Newer house so temps are good..no drafts or cold spots in rooms.

As for yeast I just use the two slap packs

Ah, two areas of improvement.

The thermometer can be as simple as the very capable long probe mechanical sold by MoreBeer for like $15. Mine off -1 degree at boiling and and +2 with melted ice bath. I could have adjusted it but that is so close I saw no reason.

A refractometer can be relatively accurate for fermented beer but there are more than one correction factor when alcohol is present. Just use a cheap hydrometer and check it against distilled water.

It may be that you FG is just fine.

 

[chickypad]

You have an IPA that started at 1.048?
At any rate, as mentioned above you need to do the corrections for a refractometer sample that has alcohol present. I'm guessing your readings were something like 12 Brix OG, and 6.3 or so post fermentation? In unfermented wort that 6.3 is about 1.025, but in a wort that started at 12 Brix it's more like 1.013. There is a calculator here which uses Sean Terrill's formula which works pretty well for my refractometer when checked against hydro readings, YRMV.

 

[Tiddy]

It was more of a pale ale than an IPA..my mistake...but anyways I very much appreciate all the help and suggestions. I'll grab a hydrometer tomorrow and just use it for my FG calculations and see if they might have in fact hit the right gravities and it's just operator error. Appreciate all the quick replies with advice. I'll update tomorrow just in case someone stumbles across this thread in the future